dv_compare

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, covering the safety profile. The description adds a genuine behavioral commitment ('without inventing a conversion rate') and the rental Pareto-frontier output mode, which is useful context beyond the annotations, though it omits anything about limits, cost, or resolution of unresolved facts.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two tightly written sentences with the core action front-loaded and the rental special case second. No filler, though 'unresolved facts' is left undefined rather than being genuinely informative.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return values need not be described, but for a comparison tool with a single undocumented parameter, open-world behavior, and many overlapping siblings, the description leaves key questions unanswered: what counts as an 'unresolved fact', what the comparison yields, and how it differs from dv_rank/dv_similar.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

There is one parameter, 'listings', with 0% schema description coverage, so the schema does not compensate. The description implies the array can hold either ads or unresolved facts, which is meaningful input semantics, but it never clarifies the accepted format, identifiers, or the 10-item cap.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (compare) and resource (supplied ads), plus a distinctive behavior for rentals (deposit/rent Pareto frontier). However, it does not distinguish itself from the many similar siblings like dv_rank, dv_similar, or dv_assess_price, and 'unresolved facts' is unexplained jargon.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The phrase 'For rentals' hints at a conditional mode, but there is no guidance on when to choose dv_compare over dv_rank, dv_similar, or dv_assess_price, and no prerequisites or exclusions are stated.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.